American P-51 Mustang in flight
The P-51 Mustang is a single-seat fighter aircraft used on Earth, by the United States of America, during the Second World War. It was primarily used for bomber escort. It was well-armed, with six .50 caliber machine guns in its wings. (ENT: "Storm Front")
When attempting to land in San Francisco in an alternate timeline, Commander Tucker and Ensign Travis Mayweather were fired upon in their shuttlepod by three P-51s. (ENT: "Zero Hour", "Storm Front")
Background
The P-51 Mustangs in "Zero Hour" and "Storm Front" were digitally rendered creations, visualized by effects artist Koji Kuramura at Eden FX. Although the sequence of "Zero Hour" in which they appear was scripted to be set circa 1942, the visual effects team did some research and found that this type of airplane clashed with that chronological setting. "We realized there were no P-51 Mustangs in 1942 San Francisco," explained Eden FX staff member Robert Bonchune. "But there would have been P-38-era Cobras and P-38s." Faced with this contradiction, executive producer Rick Berman decided that the sequence would instead be set in 1944, so that the P-51s could be included. (Star Trek Magazine issue 118, p. 31)